Satyajit Ratha

We developed hierarchical nanostructured composites integrating transition-metal chalcogenides with conductive carbon frameworks, which have emerged as promising platforms due to their enhanced electrochemical activity and excellent stability.

Smart self-healing polymers offer sustainable solutions for energy storage and sensing by autonomously repairing damage while enhancing durability and reliability, and enabling next-generation power devices and flexible electronic skin sensors.

We developed a CoSb ₂ O ₆ /rGO composite electrode for energy storage. Electrochemical tests show improved charge-storage performance, excellent stability, and high-power density, showcasing its potential for advanced supercapacitors.

The corrosion protection of metals has long been considered a key challenge for researchers at both industrial and academic levels. While numerous state-of-the-art corrosion protection techniques exist for metals like copper, iron, steel, and zinc, there are few reports on preventing aluminum (Al) from corrosion. This study introduces an innovative method for protecting aluminum from corrosion through the anodic electrochemical deposition of reduced graphene oxide (rGO) coatings. The anti-corrosion performance of rGO-coated aluminum (Al/rGO) substrates was examined in 1.0 M hydrochloric acid (HCl) and 1.0 M sodium chloride (NaCl) solutions, utilizing electrochemical techniques. The in situ reduction of the graphene oxide (GO) coatings has shown significantly enhanced corrosion protection for aluminum compared to uncoated surfaces. The experimental findings demonstrate that rGO coatings protect against corrosive substances due to their hydrophobicity, diffusion site blockage, and tortuous diffusion path mechanisms on the aluminum surface. Additionally, to gain further insight into this study, with the help of density functional theory (DFT), analysis has revealed the weaker binding of corrosive species, such as NaCl−, HCl molecules, and Cl⁻ ions with graphene- as well as rGO-coated Al surfaces (Al/Gr and Al/rGO) in comparison to their stronger binding with the uncoated Al surface. The diffusion energy barrier study has shown that the corrosive species must go through a high diffusion energy barrier to react with Al/Gr and Al/rGO surfaces compared to the bare Al surface. The combined experimental and theoretical studies found that rGO strongly binds with the Al surface, thus providing favorable corrosion protection for the bare Al surface.

Experimental and theoretical insights into the comparative electrochemical charge storage performances of a NiSb ₂ O ₆ –reduced graphene oxide composite, with its bare counterpart, in neutral electrolytic medium.

Materials Horizons and Nanoscale Horizons Community Board members Edison Huixiang Ang and Satyajit Ratha introduce their Community Board collection, highlighting some of the exceptional and timely research in the fields of energy storage and energy harvesting published in the journals.

We present here a selective and focused review of various Effective Medium Theories (EMT) with their progressive developments, and different mixture formulae used to calculate one of the most important optical constants, i.e. effective permittivity, for different composites. First, we visit the well-known Maxwell Garnett (MG) EMT and its variants. Thereafter, we discuss MG-EMT for the inclusions such as bi-anisotropic materials, carbon nanotube, uniaxial, and anisotropic materials. Then we emphasise the Bruggeman (Br) EMT and its variants. We have also discussed Br-EMT for uniaxial inclusions. In the next section, we analyse Bragg-Pippard (BP) EMT for anisotropic dielectric homogenized composite medium and for bi-anisotropic system. Next, we discuss on Strong Property Fluctuation Theory (SPFT) for bi-anisotropic ellipsoidal inclusions. Following this, we consider EMT for dielectric-magnetic materials, and for thin multilayer structures. Finally, we discuss different mixture formulae used for colloidal solutions, gas mixtures, solvent mixtures, and electrolyte solutions.

This work reports the hybridization of patronite (VS₄) sheets with reduced graphene oxide and functionalized carbon nanotubes (RGO/FCNT/VS₄) through a hydrothermal method. The synergistic effect divulged by the individual components, i.e., RGO, FCNT, and VS₄, significantly improves the efficiency of the ternary (RGO/FCNT/VS₄) hybrid toward the oxygen evolution reaction (OER). The ternary composite exhibits an impressive electrocatalytic OER performance in 1 M KOH and requires only 230 mV overpotential to reach the state-of-the-art current density (10 mA cm^–2). Additionally, the hybrid shows an appreciable Tafel slope with a higher Faradaic efficiency (97.55 ± 2.3%) at an overpotential of 230 mV. Further, these experimental findings are corroborated by the state-of-the-art density functional theory by presenting adsorption configurations, the density of states, and the overpotential of these hybrid structures. Interestingly, the theoretical overpotential follows the qualitative trend RGO/FCNT/VS₄ < FCNT/VS₄ < RGO/VS₄, supporting the experimental findings.